import React from 'react';
class Btn extends React.Component{
  render(){
    console.log(this.props)
    // 组件内部返回的结构
    return (
      <button>{this.props.msg}</button>
    )
  }
}
function App() {
  return (
    <div className="App">
      <Btn msg="点一下班长头发掉一根"></Btn>
    </div>
  );
}
export default App;
